| Popis: |
It is now 8 years since I commenced observations upon the Glacial phenomena of the Cleveland area—using the term in its broadest sense as including the whole of the Jurassic mass of North-eastern Yorkshire, but no results were attained in the first 5 years. The investigation, however, of a tract of country on the western edge of the Yale of York familiarized me with many of the more patent signs of old glacier-lakes, especially the phenomena of abandoned overflows, and this experience enabled me to recognize the great Newton-Dale valley as belonging to this category. Following this clue backward, I discovered the great system of lakes and related phenomena now to be described. The progress of the investigation of the area west of the Ouse has been briefly recorded in papers submitted to the British Association, and on various occasions has been communicated to the Yorkshire Geological & Polytechnic Society. A new stimulus to these studies was given by Prof. W. M. Davis, who accompanied me in the examination of a tract of country round Knaresborough, where an extra-morainic diversion of the River Nidd and some other lake-overflows are well displayed. Prof. Davis on that occasion mentioned some work of a like nature which was engaging the attention of Prof. G. K. Gilbert; and I am impelled to mention the fact, as this statement of Prof. Gilbert9s views undoubtedly aided me, to how great an extent I am unable to say. II. Modern Extra-Morainic Lakes Whenever a glacier or ice-sheet |
